util/qualcomm/qgpt.py

   1 #!/usr/bin/env python3
   2 #============================================================================
   3 #
   4 #/** @file qgpt.py
   5 #
   6 # GENERAL DESCRIPTION
   7 #   Generates QCom GPT header for wrapping Bootblock
   8 #
   9 # Copyright (c) 2018, The Linux Foundation. All rights reserved.
  10 #
  11 # SPDX-License-Identifier: BSD-3-Clause
  12
  13 #**/
  14 #
  15
  16 import os
  17 import math
  18 import random
  19 import re
  20 import struct
  21 import sys
  22 import tempfile
  23
  24 from binascii import crc32
  25 from optparse import OptionParser
  26 from types import *
  27
  28
  29 def UpdateMBR(options, GPTBlobBuffer):
  30     i = 0x1BE
  31     GPTBlobBuffer[i + 0] = 0x00                  # not bootable
  32     GPTBlobBuffer[i + 1] = 0x00                  # head
  33     GPTBlobBuffer[i + 2] = 0x01                  # sector
  34     GPTBlobBuffer[i + 3] = 0x00                  # cylinder
  35     GPTBlobBuffer[i + 4] = 0xEE                  # type
  36     GPTBlobBuffer[i + 5] = 0xFF                  # head
  37     GPTBlobBuffer[i + 6] = 0xFF                  # sector
  38     GPTBlobBuffer[i + 7] = 0xFF                  # cylinder
  39     GPTBlobBuffer[i + 8:i + 8 + 4] = [0x01, 0x00, 0x00, 0x00]
  40
  41     GPTBlobBuffer[i + 12:i + 16] = [0x00, 0x0f, 0x00, 0x00]
  42
  43     # magic byte for MBR partitioning - always at this location regardless of
  44     # options.sector
  45     GPTBlobBuffer[510:512] = [0x55, 0xAA]
  46     return i
  47
  48
  49 def UpdatePartitionEntry(options, GPTBlobBuffer):
  50
  51     i = 2 * options.sector_size
  52     # GUID of Boot Block
  53     GPTBlobBuffer[i:i + 16] = [0x2c, 0xba, 0xa0, 0xde, 0xdd, 0xcb, 0x05, 0x48,
  54         0xb4, 0xf9, 0xf4, 0x28, 0x25, 0x1c, 0x3e, 0x98]
  55     i += 16
  56
  57     #This is to set Unique Partition GUID. Below Hex Value is : 00ChezaBootblock00
  58     GPTBlobBuffer[i:i + 16] = [0x00, 0x43, 0x68, 0x65, 0x7a, 0x61, 0x42, 0x6f,
  59         0x6f, 0x74, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x00]
  60     i += 16
  61
  62     # LBA of BootBlock Start Content
  63     GPTBlobBuffer[i:i + 8] = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
  64     i += 8
  65
  66     # End LBA of BootBlock Content
  67     GPTBlobBuffer[i] = options.end_lba & 0xFF
  68     GPTBlobBuffer[i+1] = (options.end_lba>>8) & 0xFF
  69     GPTBlobBuffer[i+2] = (options.end_lba>>16) & 0xFF
  70     GPTBlobBuffer[i+3] = (options.end_lba>>24) & 0xFF
  71     GPTBlobBuffer[i+4] = (options.end_lba>>32) & 0xFF
  72     GPTBlobBuffer[i+5] = (options.end_lba>>40) & 0xFF
  73     GPTBlobBuffer[i+6] = (options.end_lba>>48) & 0xFF
  74     GPTBlobBuffer[i+7] = (options.end_lba>>56) & 0xFF
  75     i += 8
  76
  77     # Attributes
  78     GPTBlobBuffer[i:i + 8] = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
  79     i += 8
  80
  81     # Label
  82     GPTBlobBuffer[i:i + 17] = [0x62, 0x00, 0x6f, 0x00, 0x6f, 0x00, 0x74, 0x00,
  83         0x62, 0x00, 0x6c, 0x00, 0x6f, 0x00, 0x63, 0x00, 0x6b]
  84
  85     return i
  86
  87 def UpdateGPTHeader(options, GPTBlobBuffer):
  88
  89     i = options.sector_size
  90     # Signature and Revision and HeaderSize i.e. "EFI PART" and 00 00 01 00
  91     # and 5C 00 00 00
  92     GPTBlobBuffer[i:i + 16] = [0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54,
  93         0x00, 0x00, 0x01, 0x00, 0x5C, 0x00, 0x00, 0x00]
  94     i += 16
  95
  96     # CRC is zeroed out till calculated later
  97     GPTBlobBuffer[i:i + 4] = [0x00, 0x00, 0x00, 0x00]
  98     i += 4
  99
 100     # Reserved, set to 0
 101     GPTBlobBuffer[i:i + 4] = [0x00, 0x00, 0x00, 0x00]
 102     i += 4
 103
 104     # Current LBA
 105     GPTBlobBuffer[i:i + 8] = [0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
 106     i += 8
 107
 108     # Backup LBA, No Backup Gpt Used
 109     GPTBlobBuffer[i:i + 8] = [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
 110     i += 8
 111
 112     # First Usuable LBA (qc_sec + bootblock location)
 113     GPTBlobBuffer[i:i + 8] = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
 114     i += 8
 115
 116     # Last Usuable LBA (qc_sec + bootblock end location)
 117     GPTBlobBuffer[i] = options.end_lba & 0xFF
 118     GPTBlobBuffer[i+1] = (options.end_lba>>8) & 0xFF
 119     GPTBlobBuffer[i+2] = (options.end_lba>>16) & 0xFF
 120     GPTBlobBuffer[i+3] = (options.end_lba>>24) & 0xFF
 121     GPTBlobBuffer[i+4] = (options.end_lba>>32) & 0xFF
 122     GPTBlobBuffer[i+5] = (options.end_lba>>40) & 0xFF
 123     GPTBlobBuffer[i+6] = (options.end_lba>>48) & 0xFF
 124     GPTBlobBuffer[i+7] = (options.end_lba>>56) & 0xFF
 125     i += 8
 126
 127     # GUID
 128     GPTBlobBuffer[i:i + 16] = [0x32,0x1B,0x10,0x98,0xE2,0xBB,0xF2,0x4B,
 129         0xA0,0x6E,0x2B,0xB3,0x3D,0x00,0x0C,0x20]
 130     i += 16
 131
 132     # Partition Table Entry LBA
 133     GPTBlobBuffer[i:i + 8] = [0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]
 134     i += 8
 135
 136     # Number of Partition Entries
 137     GPTBlobBuffer[i:i + 4] = [0x01, 0x00, 0x00, 0x00]
 138     i += 4
 139
 140     # Size of One Partition Entry
 141     GPTBlobBuffer[i:i + 4] = [0x80, 0x00, 0x00, 0x00]
 142     i += 4
 143
 144     # CRC of Partition Entry
 145
 146     PartEntry = GPTBlobBuffer[options.sector_size*2:options.sector_size*2 + 128]
 147     CalcEntryCRC = crc32(b''.join(struct.pack("B", x) for x in PartEntry))
 148
 149     GPTBlobBuffer[i] = CalcEntryCRC & 0xFF
 150     GPTBlobBuffer[i+1] = (CalcEntryCRC>>8) & 0xFF
 151     GPTBlobBuffer[i+2] = (CalcEntryCRC>>16) & 0xFF
 152     GPTBlobBuffer[i+3] = (CalcEntryCRC>>24) & 0xFF
 153     i += 4
 154
 155     # CRC of Partition Table Header
 156     GPTHeader = GPTBlobBuffer[options.sector_size:options.sector_size + 92]
 157     CalcEntryCRC = crc32(b''.join(struct.pack("B", x) for x in GPTHeader))
 158     i = options.sector_size + 16
 159
 160     GPTBlobBuffer[i] = CalcEntryCRC & 0xFF
 161     GPTBlobBuffer[i+1] = (CalcEntryCRC>>8) & 0xFF
 162     GPTBlobBuffer[i+2] = (CalcEntryCRC>>16) & 0xFF
 163     GPTBlobBuffer[i+3] = (CalcEntryCRC>>24) & 0xFF
 164
 165     return i
 166
 167
 168 if __name__ == '__main__':
 169     usage = 'usage: %prog [OPTIONS] INFILE OUTFILE\n\n' + \
 170             'Packages IMAGE in a GPT format.'
 171     parser = OptionParser(usage)
 172     parser.add_option('-s', type="int", dest='sector_size', default=4096,
 173                       help='Sector size in bytes [Default:4096(4KB)]',
 174                       metavar='SIZE')
 175
 176     (options, args) = parser.parse_args()
 177     if len(args) != 2:
 178         print("Invalid arguments! Exiting...\n")
 179         parser.print_help()
 180         sys.exit(1)
 181
 182     if options.sector_size != 4096 and options.sector_size != 512:
 183         print("Invalid Sector Size")
 184         sys.exit(1)
 185
 186     options.inputfile = args[0]
 187     options.outputfile = args[1]
 188
 189     with open(options.inputfile, 'rb+') as fin:
 190       bb_buffer = fin.read()
 191
 192     # Round up to next sector if bootblock size not evenly divisible
 193     options.end_lba = ((len(bb_buffer) + options.sector_size - 1) //
 194       options.sector_size)
 195     # Add 3 sectors for MBR, GPT header and GPT partition entry
 196     options.end_lba += 3
 197     # Subtract one because this is last usable LBA, not amount of LBAs
 198     options.end_lba -= 1
 199
 200     GPTBlobBuffer = [0] * (options.sector_size*3) #Size of MBR+GPT+PART_ENTRY
 201
 202     UpdateMBR(options, GPTBlobBuffer)
 203
 204     UpdatePartitionEntry(options, GPTBlobBuffer)
 205
 206     UpdateGPTHeader(options, GPTBlobBuffer)
 207
 208     with open(options.outputfile, 'wb') as fout:
 209       for b in GPTBlobBuffer:
 210         fout.write(struct.pack("B", b))
 211       fout.write(bb_buffer)